The groundbreaking discovery of induced pluripotent stem cells (iPSCs) has opened a new page for developing personalized cell-based therapies against various devastating human diseases without ethical concerns of using human embryonic stem cells. However, the future clinical applications of iPSCs remain in doubt due to potential risks of undesired genomic alteration and tumor formation. Generation of iPSCs by transient expression of pluripotent factors has decreased the safety concerns yet the reprogramming efficiency remains low. In this application, we propose to develop an improved, cell-permeable protein-based method to efficiently generate iPSCs. We have developed a rational approach to systematically engineer, produce, and validate robust, cell-penetrating reprogramming peptides that will overcome the key barriers to achieve high-efficiency and safe cellular reprogramming. The technology will enable us to efficiently produce patient-compatible iPSCs with the best safety profiles so as to derive other cell types safely for transplantation or for other types of clinical applications. Two Aims are proposed: Specific Aim 1 (Months 1-6): To construct a library of cell permeable human iPSC reprogramming proteins with modifications that would increase their reprogramming efficiency at Vivoscript Inc. Specific Aim 2 (Months 7-12): To evaluate the efficiency of these proteins in iPSC generation in Chen's lab at Sanford-Burnham Medical Research Institute.